This paper is a social and cultural history of Modern Iran, from the perspectives of criminals and rank and file police officers. Studying the everyday lives of non-elites, subalterns, and common folk in early Modern Iran is extremely difficult, because of the lack of useable primary sources. By using police reports, crime and law-enforcement curricula and periodicals, institutional “work products” such as budgets and crime statistics, memoirs, and a wide variety of other archive documents, this paper solves this problem by studying how one of the least “elite” institutions of the state (police constables) interacted with the lowest segments of society, such as criminals, the poor, beggars, slaves, transients, etc. while at the same time studying how they intervened in domestic disputes and conflicts between merchants, laborers, servants, tradesmen, women, children, shepherds, etc. As Iran was undergoing rapid change in the late 19th and early 20th centuries, both crime and law enforcement rapidly evolved, and in many ways were completely transformed. Crime and punishment (and eventually incarceration), were redefined both conceptually and institutionally, including the replacement of earlier informal enforcement which was mostly characterized by mediation, acute coercion, negotiation, and “public spectacle” with such things as new scientifically based methods of detection and a highly bureaucratized system of criminal justice and incarceration. These changes also resulted in the emergence of a modern professional class of law-enforcement, that were defined, not just by their job, but also by broader cultural, and social ideals the helped to define them as a distinct social class different from other modern social groups, like the military, the technocrats, industrialists and professionals . Similarly new categories of crime emerged, along with a series of new professional criminal classes. Finally public cultural and political attitudes changed in accordance with broader cultural transformation underway in society. This paper uses the interface of police and criminals, and law enforcement and crime, as microcosms of broader social and cultural transformations underway in Iran during this period. Therefore, we gain a deeper understanding of how the processes of change that came with colonialism, globalization, and state-led modernization underway in society affected ordinary people and those living on “the proverbial underbelly” of society.